MiTek engineers are often asked what maximum gaps are allowed for wood member-to-wood member in metal-plate-connected wood trusses.
Gaps between wood members are addressed in Chapter 3 Quality Criteria for the Manufacture of Metal-Plate-Connected Wood Trusses of the ANSI/TPI 1-2014 (National Design Standard for Metal Plate Connected Wood Truss Construction) and cannot exceed the tolerances listed in ANSI/TPI 1. These maximum gaps range between 1/16 in. and 1/8 in. depending on where the joints are located (i.e., heel, splice).
Per section 3.7.6.1, “…maximum gaps in all joints except floor Truss chord splices shall not exceed 1/8 in., where the gap is measured at each edge of the Metal Connector Plate for joints in which the plate edge is within the scarf, and measured at the end of the scarf for joints in which the plate edge is outside the scarf. Scarf is the portion of the joint in which it is intended that there be wood-to-wood contact between two Wood Members.
The maximum gap for floor Truss chord splices shall not exceed 1/16 in. across the entire scarf.
For joints designed with single points of contact between adjacent members as shown on the Truss Design Drawing, the maximum gap between all contact points shall not exceed 1/8 in.”
For additional information, or if you have questions, please refer to ANSI/TPI 1 or contact the MiTek Engineering department.